package com.danbay.cloud.common.verifycode;

import org.apache.commons.codec.binary.Base64;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.Random;

/**
 * copy from https://github.com/frankzhuo/CheckCodeGenerate
 *
 * @author SJG
 *         2018/1/13.
 */
public class VerifyCodeGenerator {

    /**
     * 使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符
     */
    private static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
    private static Random random = new Random();


    /**
     * 验证码对象
     *
     * @author zhou-baicheng
     */
    public static class Verify {

        /**
         * 如 1 + 2
         */
        private String code;

        /**
         * //如  3
         */
        private Integer value;

        public String getCode() {
            return code;
        }

        public void setCode(String code) {
            this.code = code;
        }

        public Integer getValue() {
            return value;
        }

        public void setValue(Integer value) {
            this.value = value;
        }
    }

    /**
     * 使用系统默认字符源生成验证码
     */
    public static Verify generateVerify() {
        int number1 = new Random().nextInt(10) + 1;
        ;
        int number2 = new Random().nextInt(10) + 1;
        ;
        Verify entity = new Verify();
        entity.setCode(number1 + " x " + number2);
        entity.setValue(number1 + number2);
        return entity;
    }

    /**
     * 使用系统默认字符源生成验证码
     *
     * @param verifySize 验证码长度
     */
    public static String generateVerifyCode(int verifySize) {
        return generateVerifyCode(verifySize, VERIFY_CODES);
    }


    /**
     * 使用指定源生成验证码
     *
     * @param verifySize 验证码长度
     * @param sources    验证码字符源
     */
    public static String generateVerifyCode(int verifySize, String sources) {
        if (sources == null || sources.length() == 0) {
            sources = VERIFY_CODES;
        }
        int codesLen = sources.length();
        Random rand = new Random(System.currentTimeMillis());
        StringBuilder verifyCode = new StringBuilder(verifySize);
        for (int i = 0; i < verifySize; i++) {
            verifyCode.append(sources.charAt(rand.nextInt(codesLen - 1)));
        }
        return verifyCode.toString();
    }

    /**
     * 生成随机验证码文件,并返回验证码值
     *
     * @param w          宽
     * @param h          高
     * @param outputFile 输出文件
     * @param verifySize 验证码长度
     */
    public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException {
        String verifyCode = generateVerifyCode(verifySize);
        outputImage(w, h, outputFile, verifyCode);
        return verifyCode;
    }

    /**
     * 输出随机验证码图片流,并返回验证码值
     *
     * @param w          宽
     * @param h          高
     * @param os         输出流
     * @param verifySize 验证码长度
     */
    public static String outputVerifyImage(int w, int h, OutputStream os, int verifySize) throws IOException {
        String verifyCode = generateVerifyCode(verifySize);
        outputImage(w, h, os, verifyCode);
        return verifyCode;
    }

    /**
     * 生成指定验证码图像文件
     *
     * @param w          宽
     * @param h          高
     * @param outputFile 输出 文件
     * @param code       验证码
     */
    public static void outputImage(int w, int h, File outputFile, String code) throws IOException {
        if (outputFile == null) {
            return;
        }
        File dir = outputFile.getParentFile();
        if (!dir.exists()) {
            dir.mkdirs();
        }
        try {
            outputFile.createNewFile();
            FileOutputStream fos = new FileOutputStream(outputFile);
            outputImage(w, h, fos, code);
            fos.close();
        } catch (IOException e) {
            throw e;
        }
    }

    private static String addUrlType(String stringBase64, String fileType) {
        return "data:image/0;base64,".replace("0", fileType) + stringBase64;
    }

    private static String toBase64FormBytes(byte[] bytes) throws IOException {
        return addUrlType(new String(Base64.encodeBase64(bytes), "UTF-8"), "jpg");
    }

    /**
     * 生成base64字符串的验证码
     *
     * @param w 宽
     * @param h 高
     */
    public static String genBase64VerifyCode(int w, int h) throws IOException {
        String code = generateVerifyCode(4);
        byte[] bytes = genImageBytes(w, h, code);
        return addUrlType(new String(Base64.encodeBase64(bytes), "UTF-8"), "jpg");
    }

    /**
     * 生成base64字符串的验证码
     *
     * @param w 宽
     * @param h 高
     * @param code 验证码
     */
    public static String genBase64VerifyCode(int w, int h, String code) throws IOException {
        byte[] bytes = genImageBytes(w, h, code);
        return addUrlType(new String(Base64.encodeBase64(bytes), "UTF-8"), "jpg");
    }

    /**
     * 输出指定验证码图片流
     *
     * @param w    宽
     * @param h    高
     * @param os   输出流
     * @param code 验证码
     */
    public static void outputImage(int w, int h, OutputStream os, String code) throws IOException {
        BufferedImage image = genVerifyCodeImg(w, h, code);
        ImageIO.write(image, "jpg", os);
    }

    /**
     * 生成指定验证码图片字节码
     *
     * @param w    宽
     * @param h    高
     * @param code 验证码
     * @return 图片字节码
     */
    public static byte[] genImageBytes(int w, int h, String code) throws IOException {
        BufferedImage image = genVerifyCodeImg(w, h, code);
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ImageIO.write(image, "jpg", bos);
        return bos.toByteArray();
    }

    /**
     * 生成验证码图片对象
     *
     * @param w    宽
     * @param h    高
     * @param code 验证码
     * @return 图片对象
     */
    private static BufferedImage genVerifyCodeImg(int w, int h, String code) {
        int verifySize = code.length();
        BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        Random rand = new Random();
        Graphics2D g2 = image.createGraphics();
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        Color[] colors = new Color[5];
        Color[] colorSpaces = new Color[]{Color.WHITE, Color.CYAN,
                Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
                Color.PINK, Color.YELLOW};
        for (int i = 0; i < colors.length; i++) {
            colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
        }

        //设置边框色
        g2.setColor(Color.GRAY);
        g2.fillRect(0, 0, w, h);

        Color c = getRandColor(200, 250);
        // 设置背景色
        g2.setColor(c);
        g2.fillRect(0, 2, w, h - 4);

        //绘制干扰线
        Random random = new Random();
        // 设置线条的颜色
        g2.setColor(getRandColor(160, 200));
        for (int i = 0; i < 20; i++) {
            int x = random.nextInt(w - 1);
            int y = random.nextInt(h - 1);
            int xl = random.nextInt(6) + 1;
            int yl = random.nextInt(12) + 1;
            g2.drawLine(x, y, x + xl + 40, y + yl + 20);
        }

        // 添加噪点
        // 噪声率
        float yawpRate = 0.05f;
        int area = (int) (yawpRate * w * h);
        for (int i = 0; i < area; i++) {
            int x = random.nextInt(w);
            int y = random.nextInt(h);
            int rgb = getRandomIntColor();
            image.setRGB(x, y, rgb);
        }
        // 使图片扭曲
        shear(g2, w, h, c);

        g2.setColor(getRandColor(100, 160));
        int fontSize = h - 4;
        Font font = new Font("Algerian", Font.ITALIC, fontSize);
        g2.setFont(font);
        char[] chars = code.toCharArray();
        for (int i = 0; i < verifySize; i++) {
            AffineTransform affine = new AffineTransform();
            affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize / 2, h / 2);
            g2.setTransform(affine);
            g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);
        }

        g2.dispose();
        return image;
    }

    private static Color getRandColor(int fc, int bc) {
        if (fc > 255) {
            fc = 255;
        }
        if (bc > 255) {
            bc = 255;
        }
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }

    private static int getRandomIntColor() {
        int[] rgb = getRandomRgb();
        int color = 0;
        for (int c : rgb) {
            color = color << 8;
            color = color | c;
        }
        return color;
    }

    private static int[] getRandomRgb() {
        int[] rgb = new int[3];
        for (int i = 0; i < 3; i++) {
            rgb[i] = random.nextInt(255);
        }
        return rgb;
    }

    private static void shear(Graphics g, int w1, int h1, Color color) {
        shearX(g, w1, h1, color);
        shearY(g, w1, h1, color);
    }

    private static void shearX(Graphics g, int w1, int h1, Color color) {

        int period = random.nextInt(2);

        int frames = 1;
        int phase = random.nextInt(2);

        for (int i = 0; i < h1; i++) {
            double d = (double) (period >> 1)
                    * Math.sin((double) i / (double) period
                    + (6.2831853071795862D * (double) phase)
                    / (double) frames);
            g.copyArea(0, i, w1, 1, (int) d, 0);
            g.setColor(color);
            g.drawLine((int) d, i, 0, i);
            g.drawLine((int) d + w1, i, w1, i);
        }

    }

    private static void shearY(Graphics g, int w1, int h1, Color color) {

        // 50;
        int period = random.nextInt(40) + 10;

        int frames = 20;
        int phase = 7;
        for (int i = 0; i < w1; i++) {
            double d = (double) (period >> 1)
                    * Math.sin((double) i / (double) period
                    + (6.2831853071795862D * (double) phase)
                    / (double) frames);
            g.copyArea(i, 0, 1, h1, 0, (int) d);
            g.setColor(color);
            g.drawLine(i, (int) d, i, 0);
            g.drawLine(i, (int) d + h1, i, h1);

        }

    }

    public static void main(String[] args) throws IOException {
//        File dir = new File("D:/verifies");
//        int w = 200, h = 80;
//        for (int i = 0; i < 50; i++) {
//            String verifyCode = generateVerifyCode(4);
//            File file = new File(dir, verifyCode + ".jpg");
//            outputImage(w, h, file, verifyCode);
//        }
        int w = 100, h = 40;
        System.out.println(genBase64VerifyCode(w, h));
    }


}